What is this problem?

We have a Magnolia tree which is about 1.5m high. It is well established (been here since we moved in 13 years ago).
It has flowered most years we remember except for the last 2.

Looking at it there appears to be some fungus on the bark, and some of the leaves do have a browning to them (since early summer).

Anyone any idea what the problem is, and how we could treat it as it used to be such a magnificent tree.

Any suggestions appreciated.

 

Hi pewe

It's not fungus on the bark, but lichen - a harmless epiphitic organism that is simply using the tree as a place to grow on.

Leaf necrosis is can be caused by a disruption in the normal flow of water and nutrients from the ground up in the branches of the tree. Has there been any injury to the tree or its roots at all? Is there sign of bacterial/fungal infections? I.e. bleeding lesions, split or damaged bark, oozing sap or water? Would it be possible for you to take some more, clearer photos of the stem of the tree?

 

Thanks Harmony.

I'm glad the 'growth' is not too much to worry about. (If I understood what you are saying).

I will inspect the tree further tomorrow and take some more pics and post them.

Thanks again.

 

Yep it's just Lichen (a very interesting organism which is a partnership between a fungi and a photosynthetic partner usually an Algae or sometimes a Bacteria) the only way it could effect the tree is if there was so many of them that it blocked light getting to the leaves and your a long way off that as far as I can see there a sign of good air quality and low pollution

Here's a couple of pictures I took whilst in the West Coast of Scotland


IMG_20100922_115323 by carlbullock, on Flickr

as you can see a lot of the tree branches where just covered, it was quite breath taking on this scale


IMG_20100922_115331 by carlbullock, on Flickr

 

I have uploaded an image of the tree to this address.

http://www.uko.com/files/magnolia.jpg

It is a large image so can be viewed full size, from which you can see that there does not appear to be any problems with the tree other than the discoloration of the leaves and presence of the Lichen.

There has been no damage to the tree roots directly, but as you can see from the third picture in my original post, there was an extension built next to it. The footings were dug in the autumn of the year before it first did not flower.

From earlier comment, it may therefore be that the plant is still suffering from the interference to the ground near its roots. If that is the case, is there anything we can do now or in the spring to assist its recovery and re-flowering.

Also if there is anything we should be considering as a possible remedy for the leaf discoloration, please let us know.

If there is anything else that may be the cause of the problem, we'd welcome any suggestions.

 

Thanks for the additional photos. It looks like that the tree is suffering from potassium deficiency as well as recovering from root damage. I'd recommend ensuring the tree is watered and fed well before the winter so it builds up good energy reserves. Maybe an addition of mycorrhizal fungi at some point would also help the trees roots absorb more water and nutrients from the soil.

 

mycorrhizal fungi cannot be administered by applying the powder to the base of the tree ... this will not work from what I understand

one method is to plant 'host' plants around the base (such as perennials/ferns etc and use the fungi on these plants) which will eventully 'target' the roots of the host tree, but this may take time

there is another method but I am not sure how it works (have not read deeply), but it is available on google

 

I think you water it in don't you? I know when cultivating coniferous trees in pot's it can be added to the irrigation system

 

I never said that it could. There are various methods of adding beneficial fungi to the tree such as auger holes, compressed air and injection.

 

we are still learning, so please inform us on how one uses the fungii on existing established plants/shrubs

 

In arboriculture mycorrhizae are usually introduced into the soil via a system called terraventing. This involves first using a compressed air lance to drive air (or sometimes an air/nitrogen mix) into the soil. This immediately breaks up any compacted soil, so benefiting the tree. Secondly, a liquid solution of mycorrhizal spores and soil conditioners is injected into the broken-up earth.

Obviously, in the case here with the small magnolia, terraventing may not be a practicable solution. Instead mycorrhizal spikes (Myco Spikes) may be a suitable alternative. These solid spikes are driven into the ground and release micro- and macronutrients as well as a number of mycorrhiza species into the soil. Such spikes can be found here: MYCOspikes Fertiliser pack of 5 - Landscaping Fertilisers - Amenity Land Solutions

Ready-to-mix powder forms are also available.

 

Thank you all for your input.
I am sorry for not replying sooner, but for some reason I get no notification of replies even though my preferences are set to instant e-mail notification for replies.

I am a it surprised that lack of water may be part of the problem as there is a roof gutter down pipe which disperses onto the ground right next to the plant (see the third picture in my OP), so if anything I would have thought maybe too much water was getting to the plant. But then again, not being even remotely experienced in gardening matters I would not be surprised if my thought was totally wrong.

I will try some of these mycorrhizal spikes and see if that helps next years bloom.

Thanks again.